This invention relates, in general, to a system for acquiring data at one location, retaining the acquired data in a storage memory, transferring the stored data upon demand to a translator removed from the point of data acquisition, and displaying the translated data through a recirculatable display as desired.
More specifically, this invention relates to a self-contained data acquisition device capable of receiving and storing analog or digital voltage signals representative of any physical function that may be expressed in terms of voltage variations. The data acquisition device is coupled to a translator upon obtaining the desired data and the information stored therein is transferred upon demand to the translator whereat the information is retained for display on an external display device such as an oscilloscope or electro-mechanical recorder. The information transferred to the translator is stored therein so that the information may be displayed in repetitive cycles as desired.
In many applications it is desirable to sample or monitor various physical functions which can be expressed in terms of varying voltage signals, either analog or digital. Certain of these applications require that such measurements or samples be made remotely due to hostile environment, such as high temperatures, vibrations, radiation, or noxious fumes. In other applications it is difficult to maintain a continuous link between the data acquisition or sampling device and the read out or display system due to the inaccessibility of placing the units in contact with the data to be monitored. Examples of such applications would be monitoring data from pasteurizers, retorts, rotating shaft equipment, or furnaces and ovens.
In certain applications such as wherein it is desired to measure the temperature of a can passing through an oven, such as is frequently encountered in a conventional can line oven, a thermocouple is attached to a can by means of leads having a length sufficient to allow the can to pass through the entire oven while the other ends of the leads are connected to a standard thermo-couple recorder to receive and display the temperature the can is subjected to while passing inside the oven. While such a system is somewhat satisfactory for use with conventional can line ovens, such a method of temperature monitoring is impractical for use in monitoring the temperatures of cans passing through a pin or brush oven.
A pin or brush oven is utilized in the process of fabricating can bodies to dry open-topped cans after they have been treated by sprays or passed through liquid baths. The oven comprises a plurality of short pins, rods or brushes secured at one end to a link chain conveyor which passes about a plurality of sprockets in multi-loop vertical paths through the oven. Open-ended cans are suspended from the free end of the pin or brush to be passed through the oven.
In monitoring the temperature of a can passing through a pin or brush oven, the method employed by a conventional can line oven is impractical because of the multi-loop can paths. Therefore, one proposed solution to this problem has been through the use of telemetering equipment using a transmitter and receiver. However, such a system is very expensive in that an antenna must be intalled in the oven and shaped to conform to the multi-loop path.
The present invention utilizes a self-contained battery-operated data acquiring device which is supported from the pin transport or conveyor adjacent to and electrically coupled with a can having a thermocouple attached thereto. At predetermined time intervals the data probe monitors the voltage output from the thermocouple and stores this temperature information in its internal history. After the data probe emerges from the oven, it is connected to a translator whereat the information is transferred from the data acquisition device or probe into the translator. The translator converts the information into a display signal for display on standard recorders. Since the chain or transport velocity is known, a plot of temperature versus time can be converted into one of temperature versus position within the oven.